Harma Valves / GZ34/5AR4-HARMA RETRO

GZ34/5AR4-HARMA RETRO Click on image(s) above to view larger

All prices contained on this page are exclusive of VAT. This is currently charged at 20% and is payable by the UK only.

Harma valves consist of a selected range of valves that are chosen after meeting stringent standards for sound quality and reliability. These valves are sourced from current production as well as some of the finest Nos valves available. Unlike our competitors no Harma valves, past or present has been made in China. Harma valves represent the finest available items of their type available.

Harma valves are tested using a range of custom designed and built test rigs which are unique to Watford valves.These unique tests are not offered by any other valve supplier in the world.

All Harma pre amp valves undergo the drive rating system; the valve undergoes a series of through tests under full operational conditions. This involves a controlled burn in process to ensure perfect stability and correct ageing. A shock and vibration test, microphoney, hum, and a balance and symmetry test.

All Harma output valves undergo our own unique real world burst testing. No other supplier tests valves this way. The burst testing process involves a series of varying timed electrical signal bursts. This runs the valves under the same stress conditions that they will meet in your amplifier especially when overdriven. All out put valves are then dual matched by us on anode current and gain. This will ensure that you get the best selected valves available anywhere in the world.
The Harma GZ34 Retro design is based on Mullard's famous military GZ34/ CV1377.
It uses Mullard's compact serrated double anode design that is carbonised for greater radiation efficiency with a double support structure for the getter.

This has a number of advantages over the large bottle design such as the Chinese and JJ rectifiers and the biggest being that its design is resilient to shock and vibration, making it an ideal choice in Vox AC30s.The Harma Retro GZ34 also provides correct rectification and works well in early Vox AC30 with no reduction in B+ voltage unlike many of the modern GZ34 on the market. At last we have a real alternative to the famous Mullard GZ34/CV1377 as this valve has a proven reliability record which is second to none.

All Harma rectifier valves undergo testing under real working condition and the voltage drop is measured between each plate and the cathode. This ensures correct conformity to design parameters under real working conditions.



Facebook Twitter Follow us on Instagram